ANSWER
$943.18
Step-by-step explanation
The value of the comic book has an exponential growth, which formula is:
![y=a(1+r)^t](https://img.qammunity.org/2023/formulas/mathematics/high-school/hql0z55j78opswz590g5wjn3nhxasndtzg.png)
Where a is the inital cost, r is the increase rate and t is the time in years.
For this problem: r = 0.1, t = 9 and a = 400. After 9 years, the cost is:
![y=400\cdot(1+0.1)^9=400\cdot1.1^9\approx943.18](https://img.qammunity.org/2023/formulas/mathematics/college/qh798grnga4h4i4f9685xsxju58vs1wnqf.png)